Alpha Omega Alpha Honor Medical Society

Risk factors and dynamics of household transmission of respiratory syncytial virus and other respiratory viruses in rural Nepal

Investigator: Emily M. Scott

Mentor: Janet Englund, MD

Pneumonia is the leading cause of death among children worldwide. Respiratory viruses are an important cause of childhood pneumonia. Transmission of respiratory viruses in households has not been well­characterized in resource­limited settings.

A subset of households in a randomized controlled study of influenza vaccine during pregnancy in rural Nepal were prospectively enrolled from May 2011 to May 2012 and surveyed weekly for symptoms of respiratory illness until 180 days post­partum. At the time of illness, nasal swabs were collected, and subsequently tested by RT­PCR for nine respiratory viruses, including respiratory syncytial virus (RSV), human metapneumovirus (hMPV), human rhinovirus (HRV), coronavirus (CoV), adenovirus (AdV), and parainfluenza virus 1­4 (PIV­1­4).

From 591 households, 920 (60%) of 1726 illness episodes were positive for at least one of the nine respiratory viruses; household transmission was documented in 66 (11%) households. Viral illness rates were highest in infants (1.03 per person­year) followed by children <5y (0.45 per person­year). HRV transmission was most common (n=47), followed by RSV (n=9), and hMPV (n=8). The virus was first detected in children ages 1­4 years in 37 (45%) of transmission episodes. Infants were involved in the transmission network in 76% of all episodes. In multivariate analysis, transmission was associated with presence of a low birthweight infant (38% vs. 21%; OR 2.14, 95% CI: 1.17­3.90), and more children between 1­4 years (1.1 vs. 0.7; OR 1.56, 95% CI: 1.14­2.14).

In a prospective surveillance study in Nepal, young children ≤ 5 years of age most commonly introduced respiratory viruses into the households. Infants were frequently involved in transmission networks. A preventive intervention that targets younger children in the household may decrease risk of transmission to young infants at highest risk for poor outcomes.

Last modified: 2/01/2017

Updated on February 3, 2017.

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